Abscisic acid is a phytohormone playing an important role in the seed dormancy and the environmental stress response. The inactivation due to catabolism of abscisic acid is predominantly controlled by abscisic acid 8′-hydroxylase CYP707A.
S-Uniconazole, a plant growth retardant, functions by inhibiting the ent-kaurene oxidase CYP701A enzyme involved in the biosynthesis of gibberellin, but S-uniconazole also inhibits CYP707A. Thus, compounds were developed for removing the CYP701A inhibitory activity from the S-uniconazole function but preserving the CYP707A inhibitory activity and named as abscinazoles. For example, it has been reported that when abscinazole-E2B, one of the abscinazoles, is applied to a plant, the endogenous abscisic acid is not decomposed and that dryness resistance is imparted to the plant (Patent Literature 1 and Non Patent Literature 1).